Vitamin K Flashcards
three souces of vitamin K
phylloquinone (K1)
menaquinone (K2)
menadione (K3)
Phylloquinone (K1) is synthesized from
plants
menaquinone (K2) is synthesized from
animal sources
menadione (K3) is synthesized from
synthetic
vitamin k is destroyed by
light and heat
Vitamin K is ______ and requires bile for micelle formation
fat soluble
absorption of vitmain K is enhanced by the presence of
fat
bile salts
pancreatic juices
phylloquinone (K1) is absorbe in the
small intestine (jejun)
menaquinons are synthesized by bacteria in the_____ and absorbed by_____
lower digestive tract
passive diffusion
phylloquinone or menaquinone is absorbed better
menaquinone
vitamin k is incorporated into____ for transport across tissues
chylomicron
once vitamin k is incorporated into chylomicron, its is delivered to:
liver
Vitamin K can be incorporated into ____ for transport to extra hepatic tissue
VLDL
vitamin k is primarily stored in the
liver
the primary function of vitamin k is to :
serve as the cofactor for a carboxylase enzyme that catalyzes the g-carboxylation of glutamic acid (Glu) residues on specific proteins
the conversion of Glu residues to g-carboxyglutamate activates these proteins by creating what
calcium binding sites
g-carboxylation of glutamic acid residues is required for the activation of 7 proteins that regulate what
coagulation of blood in the clotting cascade
what are the four clotting factors
II
VII
IX
X
what are the three anticoagulant proteins
C
S
Z
three vitamin k depends proteins have been identified where
bone
cartilage
dentine
metabolites of vitamin k are excreted
primarily in the feces via bile
vitamin k deficiency results in
impaired blood clottin
symptoms of impaired blood clotting
easy bruise, bleeding gums, hematuria, blood in stool, nosebleeds
vitamin k deficiency is uncommon in adults for what three reasons
vitamin k is widespread in food
the vitamin k cycle conserves vitamin k
bacteria that normal inhabit the LI synthesize menaquinones (K2)
greatest risk for deficiency in adults
liver disease
fat malabsorptive disorders
chronic antibiotic use
why is the risk of deficiency worse in newborns
- vitamin k is no easily transported across placental border
- newborns intestines are not yet colonized with bacteria that synthesize menaquinones
- vitamin k cycle is not fully working
- breast milk has poor vitamin k content
vitamin k in infants may result in
vitamin k deficiency bleeding - life threatening
how is VKDB treated at birth
vitamin k shot
clinical indication of vitamin k supplementation
osteoporosis
atherosclerosis
which two are not associated with toxicity
phylloquinone
menaquinone
menadione
phylloquinone
menaquinone
menadioine may cause
liver toxcity and hemolytic anemia
vitamin k supplementation should have caution with patients on what drug
warfarin (coumadin)
why should there be caution on patients taking coumadin
coumadin prevents the recycling of vitamin k by inhibiting two important reactions and creating a functional deficiency
increasing vitamin k intake _____ action of coumadin
inhibits
increasing intake of coumadin _____ action of vitamin k
inhibits
Vitamin _ toxicity has been associated with inhibition of vitamin k absorption
vitamin A
two metabolites of Vitamin _ have anti- vitamin k activity
vitamin E
